Metabolic utilization and renal handling of D-lactate in men.
Metabolic utilization and renal handling of D-lactate in men.
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DOI：
10.1016/0026-0495(85)90088-5
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发表时间：
1985-07
期刊：
影响因子：
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通讯作者：
Man S. Oh;Jaime Uribarri;Denise Alveranga;Ira Lazar;Nadine Bazilinski;Hugh J. Carroll
中科院分区：
文献类型：
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作者：
Man S. Oh;Jaime Uribarri;Denise Alveranga;Ira Lazar;Nadine Bazilinski;Hugh J. Carroll
本研究是为了研究d-乳酸和l-乳酸的肾脏处理及其在男性中的代谢程度。10名健康男性受试者静脉（IV）输注d-和l-乳酸的外消旋混合物。当各异构体输注速率为1.0 ~ 1.3 meq/kg体重时，血浆中d-乳酸浓度为1.7 ~ 3.0 meq/L， L -乳酸浓度为2.8 ~ 4.2 meq/L。在这些水平下，d-乳酸的分数排泄在40%到65%之间，而l-乳酸的分数排泄总是小于5%。在较高的输注速率（1.8 ~ 2.0 meq/kg/h）下，d-和L -乳酸的血药浓度分别达到4.5 ~ 6.0 meq/L和4.0 ~ 6.7 meq/L。d-乳酸的排泄分数为61% ~ 100%，l-乳酸的排泄分数为9% ~ 30%。当血浆d-乳酸浓度低于3.0 meq/L时，L -乳酸的重吸收基本完成，但当血浆d-乳酸浓度超过3.0 meq/L时，L -乳酸的重吸收明显受损。同样，对于给定浓度的血浆d-乳酸，当血浆l-乳酸浓度和l-乳酸排泄分数较低时，其重吸收效率高于较高时。在d-乳酸输注速率为1.0 ~ 1.3 meq/L时，约90%的输注乳酸被代谢，在更高的输注速率下，仍有75%以上的输注乳酸被代谢。结果表明，1-乳酸和d-乳酸相互干扰其肾小管重吸收，且l-乳酸的重吸收比d-乳酸的重吸收更有效。尽管普遍认为相反，正常男性对d-乳酸的代谢利用是相当有效的。
This study was carried out to investigate the renal handing of d- and l-lactate and the extent of their metabolism in men. Ten healthy male subjects were given an intravenous (IV) infusion of a racemic mixture of d- and l-lactate. At an infusion rate of 1.0 to 1.3 meq/kg body weight of each isomer, d-lactate achieved a concentration in plasma of 1.7 to 3.0 meq/L, and l-lactate 2.8 to 4.2 meq/L. At these levels, fractional excretion of d-lactate ranged from 40% to 65%, while fractional excretion of l-lactate was always less than 5%. At a higher infusion rate, 1.8 to 2.0 meq/kg/h, plasma concentrations of d- and l-lactate reached 4.5 to 6.0 meq/L, and 4.0 to 6.7 meq/L, respectively. Fractional excretion of d-lactate then ranged from 61% to 100%, while that of l-lactate ranged from 9% to 30%. At plasma concentrations of d-lactate less than 3.0 meq/L, reabsorption of l-lactate was nearly complete, but when plasma d-lactate exceeded 3.0 meq/L, reabsorption of l-lactate was considerably impaired. Similarly, for a given concentration of plasma d-lactate, its reabsorption was more efficient when the plasma l-lactate concentration and fractional excretion of l-lactate were low than when they were high. At an infusion rate of d-lactate of 1.0 to 1.3 meq/L, about 90% of the infused lactate was metabolized, and at a higher infusion rate, still more than 75% of the infused lactate was metabolized. The findings indicate that both 1- and d-lactate mutually interfere with their renal tubular reabsorption, and that reabsorption of l-lactate is much more efficient than that of d-lactate. Despite widespread belief to the contrary, the metabolic utilization of d-lactate is quite efficient in normal men.